Brilliant blue R dye is capable of suppressing amyloid fibril formation of lysozyme

Amyloid fibril formation is associated with an array of degenerative diseases. While no real cure is currently available, evidence suggests that suppression of amyloid fibrillogenesis is an effective strategy toward combating these diseases. Brilliant blue R (BBR), a disulfonated triphenylmethane compound, has been shown to interact with fibril-forming proteins but exert different effects on amyloid fibrillogenesis. These inconsistent findings prompted us to further evaluate BBR’s effect on the inhibition/suppresion of protein fibrillogenesis. Using 129-residue hen lysozyme, which shares high sequence homology to human lysozyme associated with hereditary non-neuropathic systemic amyloidosis, as a model, this study is aimed at thoroughly examining the influence of BBR on the in vitro protein fibrillogenesis. We first showed that BBR dose-dependently attenuated lysozyme fibril formation probably by affecting the fibril growth rate, with the value of IC50 determined to be ~4.39 μM. Next, we employed tryptoph...